Asphalt Paper for Roofing: A Home Depot Guide to Asphalt-Saturated Felt and Underlayment

Asphalt paper, commonly known as roofing felt or asphalt-saturated paper, plays a crucial role in protecting roofs during construction and over the long term. Home Depot offers a range of roofing felt products designed to provide a moisture barrier under shingles and other roofing materials. This guide explains what asphalt paper is, how it works, the options available at Home Depot, installation basics, and practical tips to choose the right underlayment for different climates and roof types.

Understanding Asphalt Paper And Its Uses

Asphalt paper is a heavy-duty felt mat impregnated with asphalt to render it water-resistant. It is laid over roof decking before shingles or tiles are installed, acting as a secondary barrier against moisture infiltration. There are two main categories: traditional asphalt-saturated roofing felt, and synthetic underlayment alternatives. Asphalt paper remains a cost-effective choice for many residential projects, offering reliable protection in a variety of weather conditions when installed correctly.

Key Specifications To Consider

When selecting asphalt paper, homeowners should evaluate several specifications to ensure compatibility with roofing systems and local codes. The following factors influence performance and durability:

• Weight and Ply: Common options include 15-lb, 30-lb, and 40-lb felt, indicating the felt’s weight per 100 square feet. Heavier felts generally provide better tear resistance and longer-lasting moisture protection.
• Water-Resistance: Asphalt-saturated paper aims to resist water penetration during installation and after exposure to rain. Some products also offer self-sealing properties around fasteners to minimize leak paths.
• Permeability: Lower permeability reduces moisture migration from the decking into the attic space, particularly in humid climates.
• Tear Strength: Higher tear strength helps the underlayment withstand wind uplift during installation and snowfall conditions.
• Code Compliance: Local building codes may specify minimum requirements for underlayment in terms of weight and installation method.

Home Depot Options For Asphalt Paper

Home Depot stocks a variety of asphalt paper products, including traditional roofing felt and premium underlayments. Popular brands often found in stores and online include:

• Grace: Known for durability and reliable resistance to moisture.
• GAF: Offers asphalt-saturated underlayment with good tear resistance and compatibility with many shingle systems.
• Other Private Labels: Home Depot carries store-brand options that balance cost and performance for common residential projects.

Customers should verify current stock online or in-store, as product lines and availability can vary by region and season. Many Home Depot stores also provide installation guidance and can connect customers with pro installers if needed.

Installation Basics For Asphalt Paper

Proper installation is essential to maximize the effectiveness of asphalt paper. The following steps summarize standard practice used in many residential roofing projects:

• Deck Preparation: Ensure the roof decking is clean, dry, and free of protrusions or sharp edges that could tear the felt.
• Starter Rows: Begin with a full-width starter row along eaves to ensure proper protection at the roof edge. This row should be offset from the upper layers to avoid alignment of seams.
• Proper Overlap: Overlap courses by at least 2 inches (about 50 mm) to create a continuous moisture barrier. Maintain consistent overlaps across the field sheets.
• Fastening: Use corrosion-resistant nails or staples, with recommended spacing per product instructions. Do not fasten too tightly, which can cause buckling.
• Sealing And Seams: Some products may offer self-sealing features around fasteners; ensure seams are properly overlapped and aligned to prevent water ingress.
• Ventilation And Roof Configuration: In complex roof geometry or high-wind zones, additional underlayment measures may be necessary. Follow manufacturer guidelines for edge detailing and penetrations.

Climate Considerations And Performance

Climate influences the performance and lifespan of asphalt paper. In colder regions, proper installation and adequate overlap reduce the risk of water infiltration as temperatures fluctuate. In hot and sunny climates, look for underlayments with enhanced tear resistance and UV exposure tolerance during construction. Home Depot product labels typically indicate weather resistance and recommended installation environments, helping buyers pick a suitable option for their locale.

Durability, Maintenance, And Longevity

While roofing felt is a protective layer, it is not a finished roof material. Its primary role is to act as a secondary moisture barrier during and shortly after construction. Over time, shingles or other roofing materials provide the primary waterproofing. If leaks occur or signs of wear appear in the underlayment, a professional inspection can determine whether replacement is necessary during roof maintenance or re-roofing projects.

How To Choose The Right Asphalt Paper At Home Depot

Selecting the right product involves evaluating project needs, budget, and climate. Consider the following:

• Project Type: New roof installation typically benefits from standard asphalt-saturated felt; re-roof projects may require different specifications based on deck condition.
• Local Codes: Some regions specify minimum underlayment weight or specific materials. Verify with local building departments or a Home Depot associate.
• Brand Reputation: Choose established brands with documented performance and warranty coverage.
• Storage And Handling: Asphalt paper should be stored on a dry, flat surface away from direct sunlight to preserve performance until installation.

Practical Tips For Purchasers

To maximize value and performance when buying asphalt paper at Home Depot, consider:

• Compare Unit Pricing: Evaluate price per square foot or per 100 square feet to determine the most economical option without compromising quality.
• Check For Warranties: Some products carry manufacturer warranties against defects or premature degradation when installed according to guidelines.
• Ask For Expert Guidance: In-store associate guidance can clarify product differences and installation nuances for specific roof types.
• Plan For Extras: Include fasteners, starter strips, and proper edging materials in the purchase to avoid multiple trips.

Product Comparison Snapshot

Product Type	Weight	Permeability	Typical Use	Notable Pros
Asphalt-Saturated Felt	15-40 lb	Low to moderate	Standard residential roofs	Cost-effective, widely compatible
Premium Underlayment	40 lb and higher	Low	High wind or extreme climates	Better tear resistance, durability
Synthetic Underlayment (alternative)	Light to heavy	Low	Modern roofing systems	Improved strength, easier handling

Accessibility And Where To Buy

Home Depot provides multiple avenues to purchase asphalt paper, including in-store pickups, online orders with delivery, and curbside options. Look for stocked items on the Home Depot website and verify store availability. Reading product labels and customer reviews can offer practical installation insights and long-term performance expectations.

Safety Considerations

During installation, wear appropriate PPE and follow ladder safety practices. Asphalt paper should be kept dry and protected from moisture until installation. If roof work involves heights, consider professional installation to minimize risk and ensure code-compliant application.